Automatic barriers for wheelchair lifts, which barriers convert into ramps when their platforms are in their lowermost positions, are known. Also wheelchair lifts formed by the unfolding of steps into a platform are also well known. Even automatic barriers which are controlled by the folding and unfolding of steps into a platform are known, which involve linkages to arms connected to the riser panel from the lowestmost step, such as disclosed in U.S. Pat. No. Re. 33,595 issued May 28, 1991. However, in the past these mechanisms have been quite complicated and often not sufficiently reliable to meet government safety standards.